public override UIViewController GetNextViewController(UIPageViewController pageViewController,
                                                                   UIViewController referenceViewController)
            {
                int index = ((ImageViewController)referenceViewController).PageIndex;

                return((ImageViewController)ImageViewController.ImageViewControllerForPageIndex(index + 1));
            }
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            window = new UIWindow(UIScreen.MainScreen.Bounds);

            viewController = new UIPageViewController(UIPageViewControllerTransitionStyle.Scroll,
                                                      UIPageViewControllerNavigationOrientation.Horizontal,
                                                      UIPageViewControllerSpineLocation.None, 20f);

            // kick things off by making the first page
            ImageViewController pageZero = ImageViewController.ImageViewControllerForPageIndex(0);

            viewController.SetViewControllers(new UIViewController[] { pageZero },
                                              UIPageViewControllerNavigationDirection.Forward,
                                              false, null);
            viewController.DataSource = new MyDataSource();
            window.RootViewController = viewController;
            // make the window visible
            window.MakeKeyAndVisible();

            return(true);
        }